Hives (Urticaria)
Hives (urticaria) are itchy, raised welts, classified as acute (under 6 weeks) or chronic (6 weeks or longer), per the AAAAI Joint Task Force Practice Parameter.
Symptoms
Itchy, raised, red or skin-colored welts that can appear anywhere on the body, often moving and changing shape over hours; some people also develop angioedema (deeper swelling, often around the eyes or lips).
Causes and risk
Acute hives often follow an infection, food, or medication trigger, though many cases never get a confirmed cause. Chronic hives are frequently "spontaneous" -- no external trigger identified despite testing.
How it is evaluated
Extensive testing usually isn't productive; the guideline philosophy is to test sparingly and focus on history, per the international EAACI/GA2LEN/EDF/WAO guideline.
Treatment
Second-generation (non-drowsy) antihistamines are first-line, and can be dosed up to 4 times the standard dose before considering something's not working. Omalizumab is added for chronic cases not controlled on antihistamines (FDA-approved for ages 12 and up); cyclosporine is a further option for refractory disease.
When to seek care
Hives with throat tightness, difficulty breathing, facial or tongue swelling, or dizziness are signs of anaphylaxis -- call 911 and use epinephrine immediately if available.